Dark Rift Delay noise on repeats after 2 years

nate433

nate433

Active member
Suddenly there's a fizz in the repeats only. Seems to get worse when turning the time knob up. Was pretty subtle at low settings but quite noticeable at longer times. No difference if the repeats are up or and 0, same with depth and rate

Voltages in the ICs all seems to be normal, no blown caps or anything else that seemed off with a visual inspection. Maybe a cap just went bad? Sounds like i'll have to break out the probe, but wanted to see if anyone else has seen this issue before going down that road.

Thanks!
 
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To get this thread back on track haha. Question about audio probing. I've only done it on pretty simple circuits. Following the flow of the Space Spiral is pretty easy below. But not 100% sure how to diagnose anything connected to the PT2399.

Can i just probe each pin for instance and if it dies/sounds weird then i know it's a part connected to that pin?
 

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nate433 said:
To get this thread back on track haha. Question about audio probing. I've only done it on pretty simple circuits. Following the flow of the Space Spiral is pretty easy below. But not 100% sure how to diagnose anything connected to the PT2399.

Can i just probe each pin for instance and if it dies/sounds weird then i know it's a part connected to that pin?
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Did you read through @owlexifry 's treasure trove of info in the first response?

Not sure how you got two years without noise - the rest of us all got the noise as soon as we built these.

Either way I suspect the remedies are the same. Some pt2399s may be slightly less noisy than others, so you could try swapping a few others if you have them and yours is in a socket. If that doesn't work (which it probably won't) you can try the fixes documented in those posts.
 
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Maybe start with that first link in @owlexifry ’s build report:

bschobs

Post in thread 'Dark Rift Delay - Distortion/Fuzz in Wet Signal'

I would add though that this Dark Rift is noisier than most. I've built two PT2399 delay circuits since this one and the noise isn't really an issue with them (and yeah I tried swapping out different PT2399's from different sources)
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Also, 600ms is really pushing past the limits of “sort of clean” repeats.
 
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Erik S said:
Did you read through @owlexifry 's treasure trove of info in the first response?

Not sure how you got two years without noise - the rest of us all got the noise as soon as we built these.

Either way I suspect the remedies are the same. Some pt2399s may be slightly less noisy than others, so you could try swapping a few others if you have them and yours is in a socket. If that doesn't work (which it probably won't) you can try the fixes documented in those posts.
Click to expand...
Ya i read through it and a lot of good stuff to try. The build was for a friend. So it's hard to say if the noise just started happening or he just not noticed it 🤷‍♂️. For sure going to try the green LED trick. Just was trying to do more reading/prep on my lunch break.
 
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